Process vessel with integral evaporator

ABSTRACT

A process vessel containing both an evaporation zone for evaporating a liquid feed and a treatment zone for treating the resulting vapor comprises an injector having an orifice, the orifice being in the evaporation zone, at least one evaporation surface for evaporating feed and generating vapor, the evaporation surface being located in the evaporation zone, wherein the injector orifice and the evaporation surface are positioned to prevent the formation of a drop at the orifice, a treatment zone for treating the vapor and at least one heater associated with at least a portion of the process vessel.

FIELD OF THE INVENTION

[0001] The present invention relates to one or more process vessels eachprocess vessel containing both a treatment zone and an evaporation zone;the evaporation zone for vaporizing a liquid feed within the processvessel. The present invention also relates to a single, sequential, orparallel process of vaporizing a liquid feed within the processvessel(s).

BACKGROUND OF THE INVENTION

[0002] Before a catalyst is selected for use in a commercialapplication, for example hydrocarbon reactions in petroleum refining, agreat number of catalysts may be examined for use in the envisionedapplication. A large number of newly synthesized catalytic compositionsmay be considered as candidates. It then becomes important to evaluateeach of the potential catalysts to determine the formulations that arethe most successful in catalyzing the reaction of interest under a givenset of reaction conditions.

[0003] Two key characteristics of a catalyst that are determinative ofits success are the activity of that catalyst and the selectivity of thecatalyst. The term activity refers to the rate of conversion ofreactants by a given amount of catalyst under specified conditions, andthe term selectivity refers to the degree to which a given catalystfavors one reaction compared with another possible reaction, see,McGraw-Hill Concise Encyclopedia of Science and Technology, Parker, S.B., Ed. in Chief; McGraw-Hill: New York, 1984; p. 8.

[0004] The traditional approach to evaluating the activity andselectivity of new catalysts is a sequential one. When using amicro-reactor or pilot plant, each catalyst is independently tested at aset of specified conditions. Upon completion of the test at each of theset of specified conditions, the current catalyst is removed from themicro-reactor or pilot plant and the next catalyst is loaded. Thetesting is repeated on the freshly loaded catalyst. The process isrepeated sequentially for each of the catalyst formulations. Overall,the process of testing all new catalyst formulations is a lengthyprocess at best.

[0005] Combinatorial chemistry deals mainly with the synthesis of newcompounds. For example, U.S. Pat. No. 5,612,002 B1 and U.S. Pat. No.5,766,556 B1 teach an apparatus and a method for simultaneous synthesisof multiple compounds. Akporiaye, D. E.; Dahl, I. M.; Karlsson, A.;Wendelbo, R. Angew Chem. Int. Ed. 1998, 37, 9-611 disclose acombinatorial approach to the hydrothermal synthesis of zeolites, seealso WO 98/36826.

[0006] Combinatorial methods present the possibility of substantiallyincreasing the efficiency of catalyst evaluation. Recently, efforts havebeen made to use combinatorial methods to increase the efficiency anddecrease the time necessary for thorough catalyst testing. For example,WO 97/32208-A1 teaches placing different catalysts in a multi-cellholder with the heat absorbed or liberated in each cell being measuredto determine the extent of each reaction. Thermal imaging has also beenused; see Holzwarth, A.; Schmodt, H.; Maier, W. F. Angew. Chem. Int.Ed., 1998, 37, -47, and Bein, T. Angew. Chem. Int. Ed., 1999, 3-3.Measuring the heat absorption or liberation and thermal imaging mayprovide semi-quantitative data regarding activity of the catalyst inquestion, but they provide no information about selectivity.

[0007] Some attempts to acquire information as to the reaction productsin rapid-throughput catalyst testing are described in Senkan, S. M.Nature, July 1998, 4(23), 3-353, where laser-induced resonance-enhancedmultiphoton ionization is used to analyze a gas flow from each of thefixed catalyst sites. Similarly, Cong, P.; Doolen, R. D.; Fan, Q.;Giaquinta, D. M.; Guan, S.; McFarland, E. W.; Poojary, D. M.; Self, K.;Turner, H. W.; Weinberg, W. H. Angew Chem. Int. Ed. 1999, 4-8 teachusing a probe with concentric tubing for gas delivery/removal andsampling. Only the fixed bed of catalyst being tested is exposed to thereactant stream, with the excess reactants being removed via vacuum. Thesingle fixed bed of catalyst being tested is heated and the gas mixturedirectly above the catalyst is sampled and sent to a mass spectrometer.

[0008] Attempts have been made to apply combinatorial chemistry toevaluate the activity of catalysts. Some applications have focused ondetermining the relative activity of catalysts in a library; see Klien,J.; Lehmann, C. W.; Schmidt, H.; Maier, W. F. Angew Chem. Int. Ed. 1998,37, 39-3372; Taylor, S. J.; Morken, J. P. Science, April 1998, 0(10),7-270; and WO 99/34206-A1. Some applications have broadened theinformation sought to include the selectivity of catalysts. WO99/19724-A1 discloses screening for activities and selectivities ofcatalyst libraries having addressable test sites by contacting potentialcatalysts at the test sites with reactant streams forming productplumes. The product plumes are screened by passing a radiation beam ofan energy level to promote photoions and photoelectrons which aredetected by microelectrode collection. WO 98/07026-A1 disclosesminiaturized reactors where the reaction mixture is analyzed during thereaction time using spectroscopic analysis.

[0009] In order to determine the activity and selectivity of multiplecatalysts, arrays of reactors have been designed to simultaneouslyexamine multiple catalysts using the above mentioned analysistechniques. For example, EP 1108467 A2 teaches reactors with removablesections to allow easy introduction of catalyst to the reactor bed. Thereactors are sealed using o-rings to allow quick connection of thereactor parts and also provide a reliable seal between the reactor partsand between each reactor and its environment.

[0010] Many reactors available currently are designed for the situationwhere the feed streams are all of the same phase, for example two feedcomponents that are both gases. Many process technologies andchemistries require higher-pressure gas-phase catalysis, in which aliquid feedstock is vaporized before contacting the catalyst. This maybecome challenging due to the fact that many seals used forcombinatorial arrays have a temperature limitation that is below thebubble point of many reactor inlet compositional mixtures. For example,the long-term temperature limitation on a typical O-ring seal is about170° C., while the bubble point of C₆ to C₉ hydrocarbons, for exampletoluene, at operating pressures of about 300 psig (2172 kPa) to about450 psig (3220 kPa) are between about 180° C. and about 240° C. at ahydrogen to toluene molar ratio between about 1 and about 3.

[0011] U.S. Pat. No. 5,453,526 B1 teaches a catalytic reactor whereliquid media can be continuously introduced, evaporated, and fed to acatalytic reaction. U.S. Pat. No. 3,359,074 teaches a polycondensationsystem of a single vertically extending column which is transverselypartitioned to define, in descending order, a reaction chamber, anevaporator chamber, and a finishing chamber. Two articles, Bej K. S.;Rao, M. S. Ind. Eng. Chem. Res., 1991 30 (8), 1819-1832, and Eliezer K.F.; Bhinde, M.; Houalla, M.; Broderick, D.; Gates, B. C.; Katzer, J. R.;Olson, J. H. Ind. Eng. Chem. Fundam., 1977, 16 (3), 380-385 show whereadditional particles are used to aid in flow distribution before a feedis contacted with a catalyst. What is needed is an evaporator that canbe integrated into a process vessel, that accommodates a liquid feed sothat the seals will not be compromised during operation of the processvessel, while providing for the feed to be in a vapor phase duringreaction.

[0012] However, evaporators in general have some inherent problemsassociated with their operation. One problem associated with evaporatorsin general is non-uniform mixing of a liquid feed and a gas feed.Non-uniform mixing may occur when both a gas and a liquid are introducedto an evaporator through a common inlet. The dual feed of liquid and gascauses alternating regions of gas entrainment and liquid pulsation beingintroduced to an evaporator, and therefore regions of low concentrationof the vaporized species followed by regions of high concentration ofthe vaporized species being sent to a reactor bed.

[0013] Another problem associated with non-uniform vaporization occursmainly because of a non-uniform flow of liquid into an evaporator. Inthe case of slower moving flow, a liquid issuing from an orifice into anevaporator can form droplets that detach at a regular periodicitybecause of the fluid dynamics of the liquid. The periodic formation anddetachment of droplets leads to non-uniform vaporization within theevaporator.

[0014] What is needed is an evaporator for use in a process vessel thatovercomes the problems of non-uniform mixing and non-uniformvaporization associated with evaporators in general.

BRIEF SUMMARY OF THE INVENTION

[0015] It is an object of the present invention to provide a processvessel for vaporizing a liquid feed and treating the resulting vapor inthe process vessel. It is further an object of the present invention toprovide a process of vaporizing a liquid feed and treating the vaporwithin the process vessel.

[0016] In accordance with the present invention, a process vessel isprovided for vaporizing a liquid feed within an evaporation zone beforeprocessing the feed in a treatment zone of the process vessel. Theprocess vessel includes an evaporation zone, an injector having anorifice for injecting the liquid feed into the evaporation zone, atleast one evaporation surface, a treatment zone, and a heater associatedwith a portion of the process vessel. The evaporation surface and theinjector orifice are positioned within the evaporation zone so that theevaporation surface interferes with the formation of a drop of liquidfeed at the orifice and a thin liquid film of the liquid feed is createdon the evaporation surface. The heater heats the liquid feed within theevaporation zone to a temperature sufficient to vaporize the liquidfeed. It is preferred that the evaporation surface be a bed of packing.

[0017] Further in accordance with the present invention, a process isprovided for vaporizing a liquid feed within the process vessel. Theinventive process includes the steps of providing at least oneevaporation surface in an evaporation zone of the process vessel,injecting a liquid feed into the evaporation zone through an injectororifice, heating and vaporizing the liquid feed within the evaporationzone of the process vessel. A gap formed between the injector orificeand the evaporation surface is sufficiently small so that theevaporation surface interferes with the formation of a drop of liquidfeed at the orifice. The liquid feed is instead directed to form a thinliquid film on the evaporation surface which facilitates uniformvaporization and uniform concentration in the resulting vapor. Thevaporized feed is flowed to a treatment zone of the process vessel andtreated within the treatment zone to generate an effluent. It ispreferred that the evaporation surface be a bed of packing.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0018]FIG. 1 is an exploded side view of a reactor.

[0019]FIG. 2 is a top view of a insert.

[0020]FIG. 3 is a cross-sectional side view of an assembled reactor.

[0021]FIG. 4 is a side close up view of the orifice of the injector andthe packing.

[0022]FIG. 5 is a side view of an alternative assembled reactor.

[0023]FIG. 6 is a side view of an assembled array.

[0024]FIG. 7 is a perspective view of the array and the quick connectsystem.

DETAILED DESCRIPTION OF THE INVENTION

[0025] For ease of understanding, the present invention will beexplained below in terms of the preferred embodiment where the processvessel is a reactor having an evaporation zone and a reaction zone. Itmust be understood however, that other vessels are within the generallybroad scope of the invention. Furthermore, other treatment zones inaddition to a reaction zone are within the generally broad scope of theinvention. Referring to the figures, there is shown a novel and improvedreactor 10 for evaporating liquid feed to form a vapor and reacting saidfeed in the presence of catalyst to make a product. The inventivereactor 10 prevents seals 28 and 30 and from being compromised andmaintains a reliable seal between reactor 10 and the environment whilealso providing for a liquid feed to be vaporized within reactor 10 asrequired by a reaction. Reactor 10 is particularly useful for evaluationof a catalyst 24 for a particular reaction. The inventive reactor 10 mayalso be used in an array 120 for the simultaneous reaction of a liquidfeed in the presence of several catalysts and for the evaluation ofmultiple catalysts in a combinatorial method. The integratedvaporization of the liquid feed within the reactor makes reactor 10 moreversatile than previous reactors used for the combinatorial processbecause it allows for a liquid component to be introduced to reactor 10,even if it needs to be in the vapor phase before it is contacted withcatalyst 24, and reactor 10 can perform the vaporization without seals28 and 30 failing and experimental results being compromised.

[0026] A. Reactor

[0027] Turning to FIG. 1, reactor 10 includes a housing 12 for housingreactor 10, a header 14 which provides inlets for the feed to housing12, an insert 16 attached to header 14 which retains an evaporation zone18 for vaporizing the liquid feed, an evaporator heater 20 (see FIG. 3)for providing the heat necessary to vaporize the liquid feed to form avapor, and a receptacle 22 which retains a catalyst 24, catalyst 24forming a reaction zone 26. The vapor is contacted with catalyst 24 andreacted to form a product. A gas feed may also be introduced to reactor10, mixed with the vapor in the evaporation zone 18, and reacted withthe vapor in the presence of catalyst 24 to form the product gas.

[0028] The liquid feed may be any liquid component or mixture of liquidcomponents, that is able to be vaporized under predeterminedtemperatures and pressures and is intended to undergo a reaction that iscapable of being catalyzed by catalyst 24. The feed is preferred to be aliquid hydrocarbon mixture. Examples of hydrocarbon intended for the usein reactor 10 are aromatic, aliphatic, and naphthene compounds havingsix or more carbon atoms, preferably six to nine carbon atoms. Examplesof intended feed components are benzene, toluene, xylenes, ethylbenzenes, cumene, higher alkyl substituted benzenes, cyclohexanes,cyclopentanes, higher alkyl substituted cyclic paraffins, pentanes,hexanes, heptanes, octanes, nonanes, decanes, and higher molecularweight aliphatics and mixtures of the above. Alternatively, the liquidfeedstock may be or may contain one or more components having hydrogen,carbon, and another element such as oxygen, chlorine, sulfur, nitrogen,and the like.

[0029] A gas feed is not necessary for the use of reactor 10, but isincluded in the discussions below merely to exemplify reactionsinvolving a gas feed as well as a liquid feed. The gas feed may be anygas that can activate or reactivate surface reactive sites or undergoreaction that is capable of being catalyzed by catalyst 24 and could bean organic or inorganic gas. Examples of gas feeds are hydrogen gas,oxygen gas or light hydrocarbons in the gas phase such as methane orethane. Alternatively, the gas feed could be an inert gas, such asNitrogen, to act as a carrier for the vaporized liquid feed but notintended to react in reaction zone 26. The feed to the reactor of thepresent invention may be one or more gas phase feeds, one or more liquidphase feeds, or a combination of one or more gas phase feeds and one ormore liquid phase feeds.

[0030] Both the liquid feed and the gas feed are introduced to reactor10 in measured amounts, and with known compositions so that the amountof each component being introduced to reactor 10 is known. The knownamount of each component entering reactor 10 combined with the measuredflow rate and the analyzed composition of the product gas is used todetermine the activity, feed conversion, major product and byproductselectivities and yields of catalyst 24 in reactor 10.

[0031] A first seal 28 is placed between the header 14 and the housing12 to provide a barrier between reactor 10 and its environment and asecond seal 30 is placed between the insert 16 and receptacle 22 toprevent leaks between the insert 16 and receptacle 22. The removableparts of reactor 10, along with seals 28 and 30, allow for easy assemblyand disassembly of reactor 10, as well as allowing individual parts tobe replaced if needed. For example, if receptacle 22 becomes damaged, itcan be replaced easily with an identical receptacle 22 simply by placingthe new receptacle 22 into reactor 10 and engaging seals 28 and 30.Other parts that are not damaged, do not need to be replaced. Theability of housing 12, insert 16 and receptacle 22 to be removed andreplaced allows easy assembly of reactor 10, which is beneficial for theexperimental setup of a combinatorial array 120.

[0032] Dimensions will be provided for the elements of reactor 10,however the inventive reactor 10 of the present invention is not limitedto the dimensions described below, which are provided simply for contextin the preferred case of a combinatorial-scale reactor to be used in anarray. It is conceivable that reactor 10 could be scaled up to a pilotplant or even a commercial scale or scaled down to micro-scale withoutvarying from the generally broad scope of the invention.

[0033] 1. Housing

[0034] As is best shown in FIG. 1, housing 12 includes an inlet end 32for receiving feeds and an outlet end 34 for products. Housing 12encases evaporation zone 18 and reaction zone 26. Housing 12 includes ashoulder 36 at inlet end 32 of housing 12, a main section 38 betweenshoulder 36 and outlet end 34, and a product conduit 40 at the outletend 34. Product conduit 40 is attached to housing 12 at the outlet end34 and allows a path for product to be withdrawn from reactor 10.Shoulder 36 includes a surface 42 for seal 28 to engage between housing12 and header 14. Seal 28 prevents feeds from leaking from reactor 10into the environment. Seal 28 may be retained by shoulder 36 of housing12 or it may be retained by header 14 without varying from the scope ofthe invention.

[0035] Seal 28 may be any type capable of forming a reliable,pressure-tight seal between housing 12 and header 14, but it ispreferred that seal 28 be of a type that allows quick assembly ofreactor 10. An example of an acceptable seal 28 being an elastomericO-ring, or set of O-rings engaged between housing 12 and header 14.However, typical elastomeric O-ring seals have a maximum temperaturelimitation for long-term operation of between about 170° C. and 300° C.,which is lower than the bubble points of most liquid feeds that will beintroduced to reactor 10. For example, boiling points of C₆ to C₉hydrocarbons at pressures of between about 400 psig (2860 kPa) and about500 psig (3351 kPa) range from about 300° C. and about 400° C. Note thatthe present invention is not limited to operating pressures in the rangeof 400 psig (2860 kPa) to 500 psig (3351 kPa). Reactor 10 of the presentinvention could be operated at ambient pressure or in vacuum, or atpressures higher than 500 psig (3351 kPa). The only limitation onoperating reactor pressure is a differential pressure limitation on seal28.

[0036] Because of bubble or boiling points that are higher than maximumseal limitations, many liquid feeds cannot be vaporized upstream ofreactor 10, because their elevated temperatures would compromise theintegrity of seals 28 and 30. To solve this problem, an evaporator 44 isplaced within reactor 10, downstream of seal 28 so that the maximumtemperature limitation is not reached at seal 28. It is also desirableto keep seals 28 and 30 in a cool zone that is separate from the heatedevaporation zone 18.

[0037] Housing 12 and shoulder 36 are preferably cylindrical in shape,but may be of another geometric shape. For ease of discussion, housing12 and shoulder 36 will each be described as a cylinder having a lengthand a diameter, but it must be emphasized that the invention is notlimited to a cylindrical shape having the size described herein. Othershapes and sizes of housing 12 could also be successfully employed. Forthe purpose of combinatorial use, reactor 10 is preferred to be smalland easy to manipulate so that an array 120 of multiple reactors 10 canbe assembled easily without the use of bulky parts.

[0038] In one embodiment, main section 38 of housing 12 may have alength of between about 13 cm and 14 cm and an inner diameter of betweenabout 0.4 cm and about 0.5 cm. Shoulder 36 may have a length of about1.0 cm and a diameter of between about 0.8 cm and about 1.0 cm. Productconduit 40 may have an inner diameter of less than 1 mm to about 1.5 mm.However, housing 12, shoulder 36 and product conduit 40 are not limitedto the above dimensions and could be scaled up or down without varyingfrom the scope of the present invention.

[0039] Housing 12 is preferably constructed out of a material that isinert to reaction with the liquid and gas feeds, is resistant tocorrosion, can withstand temperatures of from about 10° C. to about1000° C., and has good heat transfer properties. Examples of suitablematerials of construction include metals and their alloys, low gradesteel, stainless steels, super-alloys like Incolloy, Inconel andHastelloy, engineering plastics and high temperature plastics, ceramicssuch as silicon carbide and silicon nitride, glass, and quartz. Apreferred material of construction of housing 12 is 321 stainless steeland a preferred material of construction of shoulder 36 is 316 stainlesssteel.

[0040] 2. Header

[0041] As shown in FIG. 1, header 14 and insert 16 are connected to eachother so that header 14 and insert 16 form a single piece. Header 14 andinsert 16 may be connected by any number of methods such as threading,bolting or welding, but it is preferred that they be able to bedisengaged from one another so that packing 76 may be changed out ifdesired.

[0042] Header 14 provides fluid to inlet end 32 of housing 12. Header 14also provides a surface 46 for seal 28 to engage between header 14 andhousing 12 at shoulder 36, however seal 28 could engage between housing12 and insert 16. Header 14 includes an injector 48 for a liquid feedinlet, a gas feed inlet 50, a diluent gas inlet 52 and a guide tube 56for a thermocouple 54 to measure the temperature within reactor 10.Header 16 is received by housing 12 at inlet end 32.

[0043] It is preferred that the cross-section of header 14 be of thesame general shape as the cross-section of housing 12 so that header 14will easily fit within shoulder 36 of housing 12 within predeterminedtolerances. It is preferred that header 14 be generally cylindrical, butheader 14 could be generally of another geometric shape. For ease ofdiscussion, header 14 will be described as being generally cylindricalwith a length and a diameter. Header 14 fits within shoulder 36 ofhousing 12, engaging with seal 28, so that a portion of header 14 isabove shoulder 36 of housing 12.

[0044] The length of header 14 is preferably larger than the length ofshoulder 36 of housing 12 and the diameter of header 14 is preferablyslightly smaller than the diameter of shoulder 36 of housing 12 withintolerance limits so that an adequate seal can be formed between header14 and housing 12. The diameter of header 14 is also preferred to belarge enough so that there is enough area injector 48, gas feed inlet50, diluent gas inlet 52 and guide tube 56. In one embodiment, header 14may have a length between about 1.0 cm and about 1.5 cm and a diameterof between about 0.8 cm and about 0.9 cm. However, header 14 is notlimited to the above dimensions and could be scaled up or down withoutvarying from the scope of the present invention.

[0045] Like housing 12, header 14 is preferably constructed out of amaterial that is inert to reaction with the liquid and gas feeds, isresistant to corrosion, can withstand temperatures of from about 10° C.to about 1000° C., and has good heat transfer properties. It ispreferred that housing 12 and header 14 be made from similar, oridentical materials. Examples of suitable materials of constructioninclude metals and their alloys, low grade steel, stainless steels,super-alloys like Incolloy, Inconel and Hastelloy, engineering plasticsand high temperature plastics, ceramics such as silicon carbide andsilicon nitride, glass, and quartz. A preferred material of constructionof header 14 is 316 stainless steel.

[0046] Injector 48 passes through inlet end 32 of housing 12 via header14 and is in fluid communication with the interior of insert 16 so thatinjector 48 extends substantially into insert 16, and liquid feed isintroduced through an orifice 66 of injector 48 into insert 16.Preferably, orifice 66 is located within evaporation zone 18 so that theliquid feed is introduced directly into evaporation zone 18. Preferably,injector 48 is placed so that it is approximately centered radialywithin the insert 16. The radial centering allows for uniformdistribution of the liquid feed within evaporator 44. Injector 48 ispreferably tubular with a small inside diameter and an orifice 66. Inone embodiment the diameter of orifice 66 of injector 48 may be about0.2 mm. The length of injector 48 that is within insert 16 may be about5 cm.

[0047] Gas feed inlet 50 extends through header 14 and is in fluidcommunication with insert 16 so that a gas feed introduced to the insert16 enters upstream of a liquid feed introduced to insert 16. Diametersof gas feed inlet 50 may be larger than the diameter of liquid feedinlet. The diameter of gas feed conduit is chosen to accommodate apredetermined flow rate of gas feed. In one embodiment gas feed inlet 50may have a diameter of less than 1 mm. The length of gas feed inlet 50is approximately the same as the length of header 14.

[0048] Diluent gas inlet 52 extends through header 14 and through afluid path 68 in reactor 10 so that the diluent gas can bypass catalyst24 and dilute the product stream and prevent condensation, as discussedbelow. The diluent gas may be any gas used to dilute the product andsuppress the partial pressure of the product or unreacted feed toprevent condensation. It is preferred that the diluent gas be the samegas as the gas feed so that they may be introduced from a commonreservoir, but any gas may be used to dilute the product stream. Thediameter of diluent gas inlet 52 is chosen to accommodate apredetermined flow rate of the diluent gas. In one embodiment, diluentgas inlet 52 may have an inner diameter less than 1 mm. The length ofdiluent gas inlet 52 is approximately the same as the length of header14.

[0049] Optional thermocouple 54 is placed within reactor 10 formeasuring the temperature within housing 12. Preferably, optionalthermocouple 54 measures the temperature within reaction zone 26. In oneembodiment, thermocouple 54 is retained by a guide tube 56 in header 14and extends along the length of insert 16 and passes into receptacle 22so that a sensor 70 of thermocouple 54 is generally centered withinreaction zone 26. However, only the location of sensor 70 effects theinvention. Thermocouple 54 may be placed so that it is inserted throughthe sides of housing 12 and receptacle 22 so that sensor 70 is generallycentered within reaction zone 26.

[0050] Optional guide tube 56 provides a way for a thermocouple 54 to beeasily placed into reactor 10 to measure the temperature within reactionzone 26. The diameter of guide tube 56 depends on the diameter ofthermocouple 54. In one embodiment, the inner diameter of guide tube 56may less than 1 mm.

[0051] However, injector 48, gas feed inlet 50, diluent gas inlet 52 andguide tube 56 are not limited by the above dimensions and could bescaled up or down without varying from the scope of the presentinvention.

[0052] Guide tube 56 is preferably constructed out of a material that isinert to reaction with the liquid and gas feeds, is resistant tocorrosion, can withstand temperatures of from about 10° C. to about1000° C., and has good heat transfer properties. It is preferred thatguide tube 56 is constructed from similar or identical materials as thehousing 12 and header 14. Examples of suitable materials of constructioninclude metals and their alloys, low grade steel, stainless steels,super-alloys like Incollsy, Inconel and Hastelloy, engineering plasticsand high temperature plastics, ceramics such as silicon carbide andsilicon nitride, glass, and quartz. A preferred material of constructionof guide tube 56 is 321 stainless steel.

[0053] 3. Insert

[0054] Header 14 and insert 16 are disengageably connected so thatheader 14 and insert 16 form a single piece. Header 14 is adjacent toinsert 16 so that injector 48 and gas feed inlet 50 are in fluidcommunication with evaporation zone 18. Header 14 and insert 16 may beconnected by any number of methods such as threading or bolting, but itis preferred that they be able to be disengaged from one another so thatpacking 76 may be changed out if desired.

[0055] Header 14 and insert 16 are placed within housing 12 so that seal28 is engaged between header 14 and housing 12, sealing reactor 10 fromits environment and so that insert 16 is within receptacle 22. Insert 16is preferably removable. Insert 16 includes an inlet end 72 and anoutlet end 74. Insert 16 contains packing 76 to form a bed 78 withinevaporation zone 18 for vaporizing the liquid feed to form a vapor.Although particulate packing 76 as described is preferred, otherevaporation surfaces may be employed instead of a particulate packing 76(see below).

[0056] A fluid permeable member 80 is attached at outlet end 74 ofinsert 16 to retain packing 76, but still allow fluids, such as the gasfeed and the vapor to pass into receptacle 22 to be contacted withcatalyst 24. Fluid permeable member 80 is preferably a sintered metal,such as Hastelloy, but could be any material that is permeable to thefluids flowing into reaction zone 26 in receptacle 22 and sufficientlystrong to support packing 76. Other possible materials of fluidpermeable member 80 include glass, sintered glass, Raney metals,electro-bonded membranes, etched alloy membranes, and fine meshedscreens with gaps smaller than the minimum packing size, but largeenough to allow the gas feed and vapor to flow adequately.

[0057] Packing 76 could be in any form, so long as it interferes withthe formation of a droplet (described below) and provides surfaces 82for the liquid feed to form a thin liquid film 84. Packing 76 may beparticulate packing, as shown in FIG. 4, or it may be a prefabricated,structured monolithic packing, or it may be another means to interferewith droplet formation and provide surfaces for the formation of a thinliquid film 84, such as a metal insert placed within evaporation zone 18near orifice 66. For ease of discussion, packing 76 is described as aparticulate packing having a diameter.

[0058] Thin liquid film 84 allows efficient evaporation of the liquidfeed when heat is provided by an evaporator heater 20. Packing 76 ispreferably inert to the gas feed and the liquid feed and may be anyinert packing material, such as alumina, and preferably microporousalumina. Packing 76 may be of a uniform size with the same diameter foreach particle, or of a random size with minimum and maximum particlediameters. The minimum diameter of packing 76 is preferably larger thanthe diameter of orifice 66 of injector 48 so that packing 76 does notclog injector 48, and the maximum diameter of packing 76 should be nolarger than about 10% of the inner diameter of insert 16 to prevent theformation of wall flow along interior surface of insert 16. In oneembodiment, the diameter of packing 76 may be between about 0.21 mm andabout 0.42 mm.

[0059] Insert 16 is preferably of the same general shape as housing 12so that it will fit easily within housing 12. Insert 16 is preferablycylindrical in shape, but may be of another geometric shape. For ease ofdiscussion, insert 16 is described as a cylinder having a length and adiameter. In one embodiment, insert 16 may have a length of about 10 cmand a diameter of about 0.3 cm. The diameter of insert 16 is chosen sothat insert 16 will fit within receptacle 22 within predeterminedtolerances. Insert 16 is not limited to the above dimensions and couldbe scaled up or down without varying from the scope of the presentinvention.

[0060] Insert 16 is preferably constructed out of a material that isinert to reaction with the liquid and gas feeds, is resistant tocorrosion, can withstand temperatures of from about 10° C. to about1000° C., and has good heat transfer properties. It is preferred thatinsert 16 be constructed of a similar, or identical material as thehousing 12 and header 14. Examples of suitable materials of constructioninclude metals and their alloys, low grade steel, stainless steels,super-alloys like Incolloy, Inconel, Hastelloy, engineering plastics andhigh temperature plastics, ceramics such as silicon carbide and siliconnitride, glass, and quartz. A preferred material of construction ofinsert 16 is 321 stainless steel.

[0061] Insert 16 also provides a surface 86 for seal 30 to engagebetween insert 16 and receptacle 22. Seal 30 prevents the feeds fromleaking past catalyst 24 and prevents the diluent gas from passing intoreceptacle 22 and coming into contact with catalyst 24. Seal 30 may beretained by insert 16, header 14 or receptacle 22 without varying fromthe scope of the invention.

[0062] As with seal 28, seal 30 may be of any type capable of forming areliable, pressure tight seal between insert 16 and receptacle 22, butit is preferred that seal 30 be of a type that allows quick assembly ofreactor 10. An example being an elastomeric O-ring, or set of O-rings toengage between insert 16 and receptacle 22. However, most elastomericO-ring seals have a maximum temperature limitation that is lower thanthe bubble point of most liquid feeds that will be introduced to reactor10.

[0063] 4. Evaporator—Evaporation Zone

[0064] Because of bubble points higher than maximum seal limitations,most liquid feeds cannot be vaporized upstream of reactor 10 becausetheir elevated temperatures would compromise the integrity of seals 28and 30. To solve this problem, an evaporator 44 is placed within reactor10, downstream of seal 30 so that the maximum temperature limitation isnot reached at seal 30.

[0065] Integrating an evaporator within reactor 10 has some inherentproblems that need to be overcome in order for evaporator 44 to beeffective, and provide a vaporized gas stream with a constant anduniform composition. One of these problems is non-uniform mixing of agas feed and liquid feed, and another is non-uniform vaporization of aliquid feed. If the composition of the gas entering reaction zone 26 isnot uniform, it will create unreliable results. With one main purpose ofreactor 10 being the evaluation of catalysts, unreliable results wouldyield unreliable data on catalyst 24 for the reaction in question.

[0066] One problem associated with evaporators in general is non-uniformmixing of a liquid feed and a gas feed. One way non-uniform mixingoccurs is when both a gas and a liquid are introduced to an evaporatorthrough a common inlet. The combined feed of liquid and gas causesalternating regions of gas entrainment and liquid pulsation beingintroduced to an evaporator, and therefore regions of low concentrationof the vaporized species followed by regions of high concentration ofthe vaporized species being sent to a reactor bed.

[0067] Another problem associated with evaporators in general isnon-uniform vaporization which occurs mainly because of a non-uniformflow of liquid into an evaporator. In the case of slower moving flow, aliquid issuing from an orifice into an evaporator can form droplets thatdetach at a regular periodicity because of the fluid dynamics of theliquid. The periodic formation and detachment of droplets leads tonon-uniform vaporization within the evaporator.

[0068] A stream of liquid issuing out of an orifice can become unstabledue to capillarity. This instability results in the formation of dropsthe size of which can be accurately predicted by linear stabilityanalysis. The character of the liquid breakup at the orifice isprimarily controlled by the Weber number, We:${We} = \frac{\rho \quad {DU}^{2}}{\sigma}$

[0069] where D is the diameter of the orifice, U is the average liquidvelocity, ρ is the liquid density and σ is the surface tension. TheWeber number expresses the balance between external kinetic force andsurface force, wherein the external force on the droplet is defined by:$F_{D} = {\frac{\rho \quad U^{2}}{2} \cdot \frac{\pi \quad D^{2}}{4}}$

[0070] and the surface force of the droplet is defined by:

F _(S) =πDσ

[0071] The free interface of the droplet is stable when F_(D)<F_(S) or:${{\frac{\rho \quad U^{2}}{2} \cdot \frac{\pi \quad D^{2}}{4}} < {\pi \quad D\quad \sigma \quad {We}}} = {\frac{\rho \quad {DU}^{2}}{\sigma} < 8}$

[0072] When the Weber number is less than 8, a stable interface iscreated and uniform axi-symetric droplets form at the orifice. In thecase of reactor 10, liquid is introduced to evaporator 44 at low liquidflow rates, which result in low liquid velocities. For reactor 10, it isnot uncommon to have Weber numbers that are much less than one. At verylow Weber numbers the droplets approach static equilibrium conditions,and the droplet diameter can be very accurately predicted using theYoung-LaPlace equation:${( \frac{\pi \quad s^{3}}{6} ){g( {\rho_{L} - \rho_{G}} )}} = {\pi \quad D\quad \sigma}$

[0073] where s is the predicted diameter of the droplet, g is theacceleration of gravity, ρ_(L) is the density of the liquid, ρ_(G) isthe density of the gas, D is the diameter of the orifice and σ is thesurface tension of the liquid.

[0074] The droplet volume and liquid flow rate allow the estimation ofdroplet detachment times, in the case of reactor 10 of between about 4and about 6 seconds. The periodic detachment of droplets leads to severemalfunctioning patterns of vapor concentrations associated withnon-uniform vaporization of the droplets.

[0075] In the inventive evaporator 44 of the present invention, theproblem of non-uniform mixing is solved by feeding the liquid feed andgas feed at different locations within insert 16 so that mixing occursbetween the gas feed and liquid feed in evaporation zone 18, not ininjector 48. Liquid feed enters insert 16 through orifice 66 of injector48, where orifice 66 is a substantial distance down the length of insert16, while gas feed enters insert 16 near inlet end 72 of insert 16.Preferably, orifice 66 is located within evaporation zone 18.

[0076] To prevent periodic droplet formation and detachment, and therebysolve the problem of non-uniform vaporization, at least one evaporationsurface, such as surfaces 82 of packing 76, is placed within theinventive evaporator 44 of the present invention relative to orifice 66of injector 48 to interfere with the formation of droplets.

[0077] Evaporation surfaces other than those on packing 76 as describedmay be successfully employed in the present invention. Examples of suchevaporation surfaces include, but are not limited to, plates, a porousmonolith, a cone, and the like. The selected evaporation surface ispositioned to prevent the formation of a droplet at orifice 66 ofinjector 48. the description herein will exemplify the preferredembodiment where the evaporation surfaces are surfaces 82 of packing 76,however, one of ordinary skill in the art would readily understand theinvention as employing other suitable evaporation surfaces.

[0078] Bed 78 provides an evaporation zone 18 necessary to effectivelyvaporize the liquid feed. Evaporation zone 18 is encased within housing12. FIG. 4 shows a close up view of injector 48 and packing 76 at thepoint where the liquid feed is injected into bed 78. Injector 48includes orifice 66 with a diameter D at its terminal end. Liquid feedflows through injector 48 at a average liquid flow rate, U, that wouldresult in the periodic formation of a droplet 88 with a diameter, s, asshown in FIG. 4, where s is determined by the Young-LaPlace equation.Packing 76 is placed in close proximity to orifice 66, defining a gap 90between orifice 66 and packing 76. It has been hypothesized that if gap90 is sufficiently smaller than the predicted diameter s of droplet 88,then packing 76 will interfere with the formation of a stable interfaceand droplet 88 is not allowed to form. Instead, the liquid feed forms athin liquid film 84 on the surfaces 84 of packing 76 allowing uniformvaporization of the liquid feed. Because of the uniform vaporization, aconstant concentration of vapor is contacted by catalyst 24, resultingin accurate results obtained by reactor 10. It is preferred that gap 90be minimized to be as small as possible without plugging orifice 66 toensure that packing 76 interferes with the creation of a stableinterface of droplet 88.

[0079] Unexpectedly, a minimized gap 90 between packing 76 and orifice66 in inventive evaporator 44 of the present invention is so effectivethat attempts to reproduce non-uniform vaporization by settingevaporator heater 20 low enough so that the temperature of the liquidfeed is below its bubble point until well into bed 78 were unsuccessful.No malfunctioning concentration patterns were created by evaporator 44,despite the attempt to artificially produce them.

[0080] In order to ensure adequate flow distribution over packing 76 inbed 78, it is important to use appropriate sizes of packing 76.Diameters of packing 76 should be small enough to avoid a “wall effect”of the liquid flowing along the inner surface of insert 16. Preferably,the maximum diameter of packing 76 should be less then about 10% of theinside diameter of insert 16 to avoid wall flow. However, the minimumdiameter of packing 76 should be larger than the diameter of orifice 66to prevent clogging of orifice 66 by particles of packing 76. In oneembodiment, the diameter of packing 76 may be between about 0.21 mm andabout 0.42 mm. However, packing 76 is not limited to the abovedimensions and could be scaled up or down without varying from the scopeof the present invention.

[0081] Evaporator 44 of reactor 10 is not limited to use in a reactor.Evaporator 44 itself is novel and inventive and provides an improvementover previous evaporators. The inventive evaporator 44 of the presentinvention could also be used in another process vessel where it isdesirable to vaporize a liquid feed, followed by further processing in atreatment zone within the same process vessel. The process vessel wouldhave both an evaporation zone and a treatment zone, with the evaporationzone including the inventive evaporator 44. In the case of the presentinvention, reactor 10 is the process vessel and reaction zone 26 is thetreatment zone of the vapor.

[0082] 5. Evaporator Heater

[0083] Evaporator heater 20 provides the necessary energy to vaporizeliquid feed within bed 78. Evaporator heater 20 is associated with aportion of reactor 10. Preferably, evaporator heater 20 is associatedprimarily with evaporation zone 18 at the point where the liquid feed isinjected into bed 78 as shown in FIG. 3, although other locations may besuccessful as well. The duty of evaporator heater 20 is preferablyprovided by electrical resistive heating adjacent to housing 12.Evaporator heater 20 could be a heater block with a thickness largerthen the diameter of housing 12 so that evaporator heater 20 is placedaround housing 12 housing 12. However, evaporator heater 20 could be anyother type of heater, such as one utilizing a heat transfer fluid, andwould not vary from the scope of the invention.

[0084] Evaporator heater 20 is set at a temperature sufficient tovaporize the liquid feed within evaporation zone 18, forming a vapor.Preferably, the temperature of the liquid feed at orifice 66 is belowits bubble point, and evaporator heater 20 is set so that the liquidfeed is heated to above its bubble point within evaporation zone 18,creating a temperature gradient within evaporation zone 18. Still morepreferably, evaporator heater 20 is set so that a temperature gradientis created throughout evaporation zone 18 so that the temperature of thevapor is heated to a predetermined reaction temperature withinevaporation zone 18 before the vapor enters reaction zone 26.

[0085] In one embodiment, the thickness of evaporator heater 20 may beabout 8 mm. However, evaporator heater 20 is not limited to the abovedimensions and could be scaled up or down without varying from the scopeof the present invention.

[0086] 6. Receptacle

[0087] Referring to FIG. 3, receptacle 22 is placed within housing 12,and insert 16 is placed within receptacle 22 in a nested configurationso that seal 28 is engaged between header 14 and shoulder 36 of housing12 and seal 30 is engaged between insert 16 and receptacle 22.Receptacle 22 is preferably removable. Receptacle 22 includes an inletend 94 and an outlet end 96. A flange 98 is attached to inlet end 94.Flange 98 of receptacle 22 includes cut-out sections 102 (See FIG. 2) toallow a diluent gas to pass through. The diluent gas passes throughcut-out sections 102 in flange 98 and into a fluid path 68 formedbetween receptacle 22 and main section 38 of housing 12.

[0088] Receptacle 22 retains catalyst 24, within reaction zone 26. It iswithin reaction zone 26 that the gas feed and the vapor are contacted,at reaction conditions, with catalyst 24, where they are reacted to forma product. A fluid permeable member 104 is attached at outlet end ofreceptacle 22 to retain catalyst 24, but allow fluids, such as unreactedfeeds and product gas, to pass out of receptacle 22 and exit reactor 10out of product conduit 40. Fluid permeable member 104 is preferably asintered metal, such as Hastelloy, but could be any material that ispermeable to the fluids passing out of receptacle 22 and sufficientlystrong to support catalyst 24. Other possible materials of fluidpermeable member 104 include glass, sintered glass, Raney metals,electro-bonded membranes, etched alloy membranes, and fine meshedscreens with gaps that are smaller than the size of catalyst 24, butlarge enough to allow the unreacted feeds and product gas to flowadequately.

[0089] Catalyst 24 is selected to provide active sites for the desiredreaction. Catalyst 24 may be any material or mixture of materials thatpossibly catalyze the desired reaction, but preferably catalyst 24 is azeolite or some other type of catalyst that can be synthesized bycombinatorial methods. In one embodiment, an effective mass of catalyst24 placed within receptacle 22 of reactor 10 may range from about 1 mgto about 1 gram. However, catalyst 24 is not limited to the abovemasses, and more or less catalyst 24 could be added to reactor 10without varying from the scope of the present invention.

[0090] Reaction zone 26 is flanked by fluid permeable members 80 and 104upstream and downstream of catalyst 24 and by inner surface 106 ofreceptacle 22 on the side so that catalyst 24 remains within reactionzone 26. Reaction zone 26 has the same diameter as the inside diameterof receptacle 22. In one embodiment, reaction zone 26 may have a heightof between about 1.0 cm and about 1.5 cm.

[0091] Receptacle 22 is preferably of the same general shape as housing12 and insert 16 so that receptacle 22 may easily fit between housing 12and insert 16 within predetermined tolerances. Receptacle 22 ispreferably cylindrical in shape, but may be of another geometric shape.For ease of discussion, receptacle 22 is described as a cylinder havinga length and a diameter. The length of receptacle 22 is approximatelythe same as the length of main section 38 of housing 12. The lengths ofinsert 16 and receptacle 22 are chosen so that reaction zone 26 has itsdesired height. The diameter of receptacle 22 is chosen so that fluidpath 68 is provided between receptacle 22 and housing 12 to allow thediluent gas to bypass reaction zone 26 as shown in FIG. 3. Fluid path 68may also be formed by channels or groves in receptacle 22 or housing 12to allow the diluent gas to bypass reaction zone 26. In one embodiment,receptacle 22 may have a length of between about 10 cm and about 14 cmand a diameter of between about 0.4 cm and about 0.5 cm.

[0092] The diameter of flange 98 of receptacle 22 is preferred to beapproximately the same as the diameter of shoulder 36 of housing 12. Inone embodiment, the diameter of flange 98 of receptacle 22 may be about0.8 cm.

[0093] Receptacle 22 and reaction zone 26 are not limited to the abovedimensions and could be scaled up or down without varying from the scopeof the present invention.

[0094] Receptacle 22 is preferably constructed out of a material that isinert to reaction with the liquid and gas feeds, is resistant tocorrosion, can withstand temperatures of from about 10° C. to about1000° C., and has good heat transfer properties. It is preferred thatreceptacle 22 be constructed of a similar, or identical material ashousing 12 and insert 16. Examples of suitable materials of constructioninclude metals and their alloys, low grade steel, stainless steels,super-alloys like Incolloy, Inconel, Hastelloy, engineering plastics andhigh temperature plastics, ceramics such as silicon carbide and siliconnitride, glass, and quartz. A preferred material of construction ofreceptacle 22 is 321 stainless steel.

[0095] 7. Reaction Heater

[0096] A reaction heater 108 is placed adjacent to housing 12 so that itis associated primarily with reaction zone 26 and so that all ofreaction zone 26 is surrounded by reaction heater 108. Reaction heater108 provides heat for reaction zone 26 so that catalyst 24 and reactionzone 26 can be maintained at a controlled constant temperature. Reactionheater 108 can be any type of heater to provide the heat needed forreaction zone 26, such as an aluminum-bronze oven using electricalresistive heating.

[0097] As shown in FIG. 3, reaction heater 108 is placed around outletend of housing 12 so that all of reaction zone 26 is within the oven. Inone embodiment, reaction heater 108 may have a thickness of about 9 cmand the length of reactor 10 that is within reaction heater 108 may bebetween about 4 cm and about 6 cm. However, reaction heater 108 is notlimited to the above dimensions and could be scaled up or down withoutvarying from the scope of the present invention.

[0098] Preferably, the length of reactor 10 that is between evaporatorheater 20 and reaction heater 108 is sufficient so that the temperatureat packing 76 is substantially independent of the temperature atcatalyst 24. The temperature of the liquid feed at orifice 66 ofinjector 48 should not be affected by how reaction heater 108 is set,and the temperature within reaction zone 26 should not be affected byhow evaporator heater 20 is set. In one embodiment, the length ofreactor 10 between evaporator heater 20 and reaction heater 108 may bebetween about 2.5 cm and about 8 cm, but reactor 10 is not limited tothis dimension and could be scaled up or down without varying from thescope of the present invention.

[0099] 8. Diluent Gas and Diluent Zone

[0100] Some reaction mixtures of reactor 10 include a liquid feed or aproduct that has a high dew point. This creates a problem for a productmixture exiting reactor 10 through outlet end after leaving reactionheater 108 because the temperature of the reaction mixture decreases tobelow the mixture's dew point, causing liquid feed or product tocondense out of the gas phase. For some products, not only is the dewpoint high, but so is a freezing point, so that not only does theproduct condense out of the gas phase, but it also forms a solid, orplates along product conduit 40. Condensing or plating of product causestwo problems. First, it can block or obstruct flow through productconduit 40, and second, it alters the gas phase composition of theproduct stream. Because it is the gas phase composition that is measuredby analyzing downstream of reactor 10, condensation or plating canadversely impact experimental results determined by reactor 10.

[0101] It has been verified that the addition of a diluent gas toreactor 10 allows for a reduction in pressure for analysis of product,while preventing the condensation and plating of product. As shown inFIG. 3, diluent gas is introduced through diluent gas inlet 52 of header14. The diluent gas then passes through cut-out sections 102 in flange98 of receptacle 22 where it flows into fluid path 68 between receptacle22 and main section 38 of housing 12 so that the diluent gas bypassescatalyst 24. Fluid path 68 is in fluid communication with diluent gasinlet 52 and diluent gas mixing zone 110. Fluid path 68 may be formeddue to a difference in diameter between housing 12 and receptacle 22, asshown in FIG. 3, or housing 12 and receptacle 22 may have a smalltolerance between them and fluid path 68 may be formed by grooves orchannels in either housing 12 or receptacle 22. Grooves or channels (notshown) may also provide for more efficient heat transfer between thediluent gas and evaporation zone 18 and reaction zone 26.

[0102] The diluent gas dilutes product and unreacted feeds in mixingzone 110 downstream of reaction zone 26 and fluid permeable member 104of receptacle 22 near outlet 34 of housing 12. The addition of diluentgas dilutes the product stream in mixing zone 110, lowering theconcentration and partial pressure of trace undesirable by-products inthe reactor effluent, thus preventing condensation and/or plating andsubsequent equipment fouling.

[0103] The diluent gas may be mixed with the product stream at any pointdownstream of reaction zone 26, but it is preferred that it be mixedbefore product conduit 40 exits reaction heater 108 so that there is nopossibility of condensation or plating of product.

[0104] The diluent gas may be any gas capable of mixing with the productstream. It is preferred that the diluent gas be the same as the gas feedso that both the gas feed and the diluent gas may be introduced toreactor 10 from a common gas reservoir. Like the liquid feed and the gasfeed, diluent gas is introduced to reactor 10 in a measured amount andwith a known composition so that the amount of each component beingmixed with the product gas is known.

[0105] 9. Sampling and Analyzing

[0106] Reactor 10 is used to evaluate catalysts by determining theiractivity and selectivity. To accomplish this, at least a portion of theproduct gases flowing through product conduit 40 is analyzed by ananalyzer 112 to determine its chemical composition. In one embodiment, aportion of the product is sampled prior to analyzation by analyzer 112.The flow rate of product in product conduit 40 is also measured so thatthe amount of each species exiting reactor 10 can be determined.Analyzer 112 can use any method to determine each product gassescomposition, but preferably uses one of the following analytictechniques; spectroscopy, spectrometry, chromatography, nuclear magneticresonance, or a combination thereof.

[0107] 10. Alternative Embodiment with Cooler

[0108] Seals 28 and 30 and both have a maximum temperature limitationthat is lower than the bubble point of many liquid feeds that will beintroduced to reactor 10. In an alternative embodiment of reactor 10,shown in FIG. 5, a cooler 114 is added to maintain a temperature atseals 28 and 30 to ensure that seals 28 and 30 are not compromised.Cooler 114 is placed adjacent to housing 12 between evaporator heater 20and header 14, preferably so that cooler 114 is adjacent to both seals28 and 30. Cooler 114 is set so that the temperature of seals 28 and 30is below their maximum temperature limitation, ensuring that seals 28and 30 are not compromised.

[0109] Cooler 114 may be of any type capable of removing the heatnecessary to maintain seal temperatures below the maximum temperaturelimitation, but it is preferred that cooler be a plate heat exchangercooled with water flowing through a conduit within plate 116. Plate 116of cooler 114 may be made of any heat conducting material, but aluminumis preferred. In one embodiment the thickness of plate 116 of cooler 114may be about 1 cm and the diameter of the cooling water conduit (notshown) within plate 116 may be about 0.0625 inches. However, cooler 114is not limited to the above dimensions and could be scaled up or downwithout varying from the scope of the present invention.

[0110] B. Process of Evaporating and Reacting in a Reactor

[0111] The process by which reactor 10 vaporizes a liquid feed andreacts the resulting vapor in the presence of catalyst 24 includes thesteps of providing packing 76 in evaporation zone 18, providing catalyst24 in reaction zone 26, introducing a liquid feed to evaporation zone18, heating and vaporizing the liquid feed within evaporation zone 18 toform a vapor, flowing the vapor into reaction zone 26, and contacting,at predetermined reaction conditions, the vapor with catalyst 24 to forma product. In some cases a gas feed may also be introduced to reactor 10so that both the gas feed and the vapor are contacted with catalyst 24in reaction zone 26 to react and form a product.

[0112] The liquid feed may be any liquid component or mixture of liquidcomponents, that is able to be vaporized under a predetermined range oftemperatures and pressures and may undergo a reaction that may becapable of being catalyzed by catalyst 24. The liquid feed is preferredto be a liquid hydrocarbon. Examples of hydrocarbon intended for the usein reactor 10 are aromatic, aliphatic, and naphthene compounds havingsix or more carbon atoms, preferably six to nine carbon atoms. Examplesof intended feed components are benzene, toluene, xylenes, ethylbenzenes, cumene, higher alkyl substituted benzenes, cyclohexanes,cyclopentanes, higher alkyl substituted cyclic paraffins, pentane,hexanes, heptanes, octanes, nonanes, decanes, and higher molecularweight aliphatics and mixtures of the above. Alternatively, the liquidfeedstock may be or may contain one or more components having hydrogen,carbon, and another element such as oxygen, chlorine, sulfur, nitrogen,and the like.

[0113] It is preferred that the chemical composition of the liquid feedbe known and that the liquid feed be introduced to reactor 10 in ameasured amount so that calculations can be performed to determinecharacteristics of catalysts 24 such as activity, feed conversion, majorproduct and byproduct selectivities and yields.

[0114] The gas feed may be any gas that may undergo a reaction that iscapable of being catalyzed by catalyst 24, or that may provide astabilizing effect on the catalyst, and could be an organic or inorganicgas. Examples of gas feeds are hydrogen gas, oxygen gas, nitrogen gas orlight hydrocarbons in the gas phase such as methane or ethane. It ispreferred that the chemical composition and flow rate of the gas feedinto reactor 10 feed be known so that calculations can be performed todetermine an activity and selectivity for catalyst 24 as describedbelow.

[0115] In one process, catalyst receptacle 22 is placed containingcatalyst 24 for reacting vaporized feed within housing 12 wherereceptacle 22 is positioned within reactor 10 so that catalyst 24 iswithin reaction zone 26, insert 16 is placed containing packing 76having surfaces 82 for evaporating feed where insert 16 is positionedwithin receptacle 22 so that packing 76 is within evaporation zone 18,the liquid feed is injected into evaporation zone 18 through injector 48in a measured amount, where it passes through header 14 and into insert16. Next, liquid feed is injected through orifice 66 in injector 48 intobed 78 formed by packing 76, and forms a thin liquid film 84 on thesurfaces 82 of packing 76.

[0116] After the liquid feed is injected into bed 78 and forms thinliquid film 84, the liquid feed is heated by evaporator heater 20 whichis situated so that the liquid feed is heated at or near orifice 66.Evaporator heater 20 is set at a temperature sufficient to vaporize theliquid feed within evaporation zone 18, forming a vapor. Preferably, thetemperature of the liquid feed at orifice 66 is below its bubble point,and evaporator heater 20 is set so that the liquid feed is heated toabove its bubble point within evaporation zone 18, creating atemperature gradient within evaporation zone 18. Still more preferably,evaporator heater 20 is set so that a temperature gradient is createdthroughout evaporation zone 18 so that the temperature of the vapor isheated to a predetermined reaction temperature within evaporation zone18 before the vapor flows into reaction zone 26.

[0117] Packing 76 is provided and placed in insert 16 so that there is agap 90 defined between orifice 66 and packing 76 that is sufficientlysmall to interfere with the formation of a droplet on injector 48 atorifice 66. Instead of forming a liquid droplet, the liquid feed forms athin liquid film 84 on surfaces 82 of packing 76 which is easilyvaporized. Heat provided by evaporator heater 20 vaporizes the liquidfeed within bed 78 before it enters reaction zone 26 to contact catalyst24 and react. After being heated and vaporized, the resulting vaporflows through the remainder of evaporation zone 18 and passes throughfluid permeable member 80 and into reaction zone 26.

[0118] If a gas feed is to be introduced to reactor 10, it is introducedthrough header 14 in a measured amount and enters insert 16 at somepoint upstream of orifice 66. The gas feed is then mixed with the vaporin evaporation zone 18 and acts as a carrier gas for the vapor as theypass down the remainder of bed 78, through fluid permeable member 80 andinto reaction zone 26.

[0119] After entering reaction zone 26, the vaporized hydrocarbon feedand the gas feed, if present, as well as catalyst 24 are heated byreaction heater 108 to a predetermined reaction temperature. Reactionheater 108 provides the heat requirement, to maintain a constant,predetermined and controlled temperature in reaction zone 26. To controlthe temperature of reaction zone 26, the temperature of reaction zone 26is constantly measured by thermocouple 54. This measured temperature isthen used to control the setting of reaction heater 108. For example, ifthe temperature measured by thermocouple 54 is too high, the actualtemperature is compared with a specified temperature to create an errorbetween the two, and this error is used to lower the heater blockset-point.

[0120] After passing through fluid permeable member 80 in insert 16 intoreaction zone 26, the vaporized hydrocarbon and the gas feed quicklyreach the predetermined temperature. The vapor and gas feed arecontacted with catalyst 24 and go through at least one reaction togenerate a product mixture of a product, byproducts, and unreactedfeeds. The product mixture then flows out of reaction zone 26 throughfluid permeable member 104 and into product conduit 40, where it iscarried away from reactor 10.

[0121] A portion of the product mixture is sampled and analyzed byanalyzer 112 to determine its chemical composition. The product mixturemay be analyzed by any of the following analytic techniques;spectroscopy, chromatography, nuclear magnetic resonance, andcombinations thereof.

[0122] In an alternate embodiment, reaction heater 108 may providesufficient heat to also heat the packing 76 in evaporation zone 18. Withthe heat for the packing 76 being provided by reaction heater 108, agradient of heat may be established across packing 76. The amount ofheat provided to the packing 76 may be controlled by the positioning ofreaction heater 108 and the distance between reaction zone 26 andpacking 76.

[0123] As described above, in some cases it may be desirable to dilutethe product mixture with a diluent gas after the product has been formedin reaction zone 26 to suppress the partial pressure of one or morecomponents in the product mixture and prevent condensation into theliquid phase or plating into the solid phase. Preferably, the diluentgas is the same gas as the gas feed so that they may be introduced froma common reservoir. It is preferred that the chemical composition andflow rate of the diluent gas into reactor 10 be known so thatcalculations can be performed to determine an activity, feed conversion,major product and byproduct selectivities and yields for catalyst 24.

[0124] If it is desired, the product mixture is diluted with diluent gasin mixing zone 110 after the product mixture has passed through fluidpermeable member 104. The diluent gas may be introduced by any number ofmethods but it is preferred that the diluent gas be introduced toreactor 10 in a measured amount and bypass reaction zone 26 so that thediluent gas does not come in contact with catalyst 24. Feeding thediluent gas to reactor 10 is desirable so that the inlets for the liquidfeed, the gas feed and the diluent gas will all be introduced to theapparatus at the same general location. However, diluent gas could beintroduced to product mixture by a different method, such as a separateconduit that is in fluid communication with mixing zone 110 of fluidpermeable member 104.

[0125] After the diluent gas is introduced to product mixture, itquickly mixes with the product mixture in mixing zone 110 in productconduit 40 to suppress partial pressures of the components of theproduct mixture and forms a diluted product mixture. At least a portionof the diluted product mixture is sampled and analyzed by 112 asdescribed above.

[0126] C. Array of Multiple Reactors

[0127] Although reactor 10 by itself is an inventive and novel reactorfor vaporizing a liquid feed and reacting the resulting vapor in thepresence of catalyst 24, it is when an array 120 of two or more reactors10 is formed and operated in parallel that the present inventionprovides the fullest range of utility. An array 120 of reactors 10operated in parallel allows catalyst 24 to be tested at severaldifferent reaction conditions, or a plurality of different catalysts 24to be compared, or a plurality of feeds or feed compositions to becontacted with catalysts 24, or a combination thereof, so that theactivity and selectivity of each catalyst 24 can be calculated forvarious conditions, so that the most effective catalyst, and the optimalconditions for that catalyst, can be determined for the reaction ofinterest.

[0128] As shown in FIG. 6, an array 120 of two or more reactors 10 isprovided. Each of the reactors 10 of array 120 have all of the elementsdescribed above for reactor 10, a housing 12, a header 14, an insert 16for retaining packing 76 that forms a bed 78 within evaporation zone 18,and a receptacle 22 for retaining catalyst 24 that forms a reaction zone26. Each reaction zone 26 can consist of the same catalyst 24, andreactors 10 in array 120 can be operated at different reactionconditions, or a plurality of different catalysts 24, or blocks ofcatalysts 24, can be placed in the reaction zones 26 to compare aplurality of catalysts 24. However, only one evaporator heater 20 isprovided to heat the liquid feed at the orifices 66 of the injectors 48in each reactor 10. Evaporator heater 20 is placed so that it isassociated with each of the outside surfaces 92 of each of the housings12 in array 120.

[0129] Reactors 10 in array 120 are intended to perform the samereaction so that common liquid feed, gas feed, and diluent gas isintroduced to each reactor 10 in array 120. The liquid feed, gas feedand diluent gas are introduced to reactors 10 simultaneously so thatreactors 10 operate in parallel allowing several catalysts 24, orseveral reaction conditions, to be evaluated simultaneously, greatlydecreasing the experimental time requirement associated with testingmultiple catalysts 24 at multiple reaction conditions by conventionalmethods.

[0130] 1. Each Housing Attached to a Bottom Support Plate

[0131] Each housing 12 of array 120 can be a free-standing unit with thefeatures of housing 12 described above, or the housings 12 can be formedfrom a single tray or block of material. It is preferred that housings12 be free-standing units so individual housings 12 may be replaced asneeded due to damage or change-out. But, it is also preferred thathousings 12 be connected to a common bottom support 122 so that theplurality of housings 12 in array 120 can be moved as a single unit, asit is far more convenient to handle an assembly of one unit than toindividually manipulate multiple housings 12. Also, robotics, which isfrequently used in combinatorial applications, is more readily adaptedto manipulating a single tray. It is preferred that each housing 12 inarray 120 be constructed of the same material, but it is not necessary.Housings 12 can be constructed of the same materials as housing 12described above. It is further preferred that inserts 16 and receptacles22 be constructed of the same material as housings 12.

[0132] Bottom support 122 may provide for the connection of any numberof individual housings 12. For example, bottom support 122 may connectto 6, 8, 12, 24, 48, 96 or 384 of housings 12. Also, the full capacityof a particular bottom support 122 need not be used. For example, abottom support 122 designed to hold up to 48 of housings 12 may be usedto support only 24. Array 120 is flexible in this respect, because thenumber of reactors 10 being used by array 120 can be changed simply byadding or taking away a desired number of housings 12 from bottomsupport 122.

[0133] Bottom support 122 could be any shape or configuration capable ofsupporting the plurality of housings 12 in a desired, predeterminedpattern, but it is preferred that bottom support 122 be a plate withholes for each corresponding housing 12. As shown in FIG. 6 and FIG. 7,the plate of bottom support 122 includes a surface 124 which isgenerally planar.

[0134] As with the housing 12 itself, bottom support 122 may beconstructed of a variety of materials including metals and their alloys,low grade steel, and stainless steels, super-alloys like Incolloy,Inconel and Hastelloy, engineering plastics and high temperatureplastics, ceramics such as silicon carbide and silicon nitride, glass,quartz, Teflon polymer, nylon, and low temperature plastics such aspolyethylene, and polypropylene. It is preferred that bottom support 122be rigid enough to resist twisting from torque so that bottom support122 remains substantially planar throughout operation of array 120.

[0135] Bottom support 122 may allow for the connection of housings 12 inany number of geometrical patterns with the preferred being a grid. Itis preferred that bottom support 122 has dimensions similar to thedimensions of commonly used micro titer trays. It is preferred thatbottom support 122 be constructed of material that is able to withstandtemperatures of from about 10° C. to about 1000° C., and for manycatalytic reactions, bottom support 122 may be required to withstandtemperatures ranging from about 0° C. to about 1000° C.

[0136] 2. Each Header Attached to a Top Support Plate

[0137] Each housing 12 of array 120 has a corresponding insert 16 andheader 14 that has all of the features of insert 16 and header 14described above. Each of the headers 14 are connected to a top support126 so that each housing 12 has a corresponding insert 16 placed insidethe housing 12 to enclose the plurality of reactors 10 in array 120.Headers 14 are connected to top support 126 so that the plurality ofheaders 14 and inserts 16 can be moved as a single unit, as it is farmore convenient to handle an assembly of one unit than to individuallymanipulate multiple inserts 16. Also, because housings 12 are connectedto bottom support 122 and headers 14 are connected to top support 126,the plurality of headers 14 and inserts 16 can be moved as a singlepieces, allowing array 120 to be assembled by one step whichsimultaneously seals to form array 120.

[0138] It is preferred that each header 14 and each insert 16 of array120 be constructed of the same material, but it is not necessary.Inserts 16 may be constructed from the same materials as header 14 andinsert 16 described above. In some applications it may be preferred forheaders 14 and inserts 16 to be constructed from the same material, orsimilar material, as the corresponding housings 12.

[0139] Top support 126 may provide for the connection of any number ofindividual headers 14. For example, top support 126 may connect to 6, 8,12, 24, 48, 96 or 384 of headers 14. Also, the full capacity of aparticular top support 126 need not be used. For example, a top support126 designed to hold up to 48 of headers 14 may be used to support only24. Array 120 is flexible in this respect, because the number ofreactors 10 being used by array 120 can be changed easily simply byadding or taking away a desired number of headers 14 and inserts 16 fromtop support 126.

[0140] Top support 126 could be any shape or configuration capable ofsupporting the plurality of inserts 16 in a desired, predeterminedpattern, but it is preferred that top support 126 be a plate with holesfor each corresponding header 14. As shown in FIG. 6 and FIG. 7, theplate of top support 126 includes a surface 128 which is generallyplanar.

[0141] As with header 14 and insert 16, top support 126 may beconstructed of a variety of materials including metals and their alloys,low grade steel, and stainless steels, super-alloys like Incolloy,Inconel and Hastelloy, engineering plastics and high temperatureplastics, ceramics such as silicon carbide and silicon nitride, glass,quartz, Teflon polymer, nylon, and low temperature plastics such aspolyethylene, and polypropylene. It is preferred that top support 126 berigid enough to resist twisting and torque so that top support 126remains substantially planar throughout operation of array 120.

[0142] Top support 126 may allow for the connection of inserts 16 in anynumber of geometrical patterns with the preferred being a grid. It ispreferred that top support 126 has dimensions similar to the dimensionsof commonly used micro titer trays. It is preferred that top support 126be constructed of a material capable of withstanding temperatures from10° C. to about 1000° C., but a preferred range of temperatures includestemperatures ranging from about 10° C. to about 300° C.

[0143] 3. Receptacles

[0144] Each set of housings 12 and corresponding inserts 16 has acorresponding receptacle 22 for retaining catalyst 24 having thefeatures of the receptacle 22 described above to form a reactor 10within array 120. Each reactor 10 is assembled in the same manner asdescribed above, except that each reactor 10 is connected to a set ofsupports 122 and 124 to form array 120.

[0145] It is preferred that each receptacle 22 of array 120 beconstructed from the same material, but it is not necessary. In somecase it may also be preferred for the receptacle 22 to be constructedfrom the same material, or a similar material, as the housing 12, or thesame material, or a similar material, as the insert 16, or both.

[0146] 4. Quick Connect System Including Quick Sealing

[0147] Array 120 of reactors 10 allows for the rapid evaluation ofmultiple variables simultaneously. For example, each reactor 10 of array120 can be used to evaluate a different catalyst 24 under the samereaction pressure and temperature and with the same feed compositions,or each reactor 10 can evaluated the same catalyst 24 under varyingreaction conditions, such as multiple pressures, temperatures and feedrates and compositions. To fully realize the greatest utility, it ispreferred that array 120 include an apparatus that allows for the quickassembly and disassembly of array 120. Seals 28 and 30 aid in thisquick-connect because they allow each reactor 10 to be assembledquickly, but still prevent leaks between parts of the reactor andbetween reactor 10 and its environment. Each seal 28, 30 operates toseal the plurality of reactors 10 simultaneously. Housing support 122 isimportant because it allows the plurality of housings 12 to be moved asa single piece and insert support 126 is important because it allows theplurality of headers 14 and inserts 16 to be moved as another singlepiece. However, an apparatus is still needed to raise and lower housingsupport 122 and insert support 126.

[0148] Quick-connect system 130 provides a method to raise and lowersupports 122 and 126 while still assuring high precision in thehorizontal plane, allowing seals 28 and 30 to seal effectively in eachreactor 10. Quick-connect system 130 can be used to raise and lowerhousing support 122 with insert support 126 remaining stationary, or itcan be used to raise and lower insert support 126 with housing support122 remaining stationary, or each support can have its own quick-connectsystem and both supports 122 and 126 can be raised and lowered asdesired. For ease of discussion, quick-connect system will be describedas being used to raise and lower insert support 126 while housingsupport 122 remains stationary, as shown in FIG. 7, but as discussedabove quick-connect system 130 could be used for either support 122 or126.

[0149] One embodiment of quick-connect system 130 includes threadedguide rods 132, guide rings 134, stationary rings 136 and wheels 138.Guide rings 134 are attached to insert support 126 so that they extendaway from insert support 126. In FIG. 7, a set of two guide rods 132 areshown, each guide rod 132 having a corresponding guide ring 134,stationary ring 136 and wheel 138. Although two of each of the pieces isshown in FIG. 7, any number could be used without varying from the scopeof the present invention.

[0150] Each guide rod 132 is threaded so that when it is rotated insertsupport 126 will be raised or lowered depending on which direction guiderod 132 is rotated. Each guide ring 134 includes a hole 140 that isgenerally in the center of guide ring 134. It is preferred that hole 140be generally cylindrical in shape and extend through guide ring 134.Hole 140 is also threaded so that a corresponding threaded guide rod 132can be placed through hole 140. Guide rod 132 and hole 140 are threadedso that when guide rod 132 is rotated, guide ring 134, and thereforeinsert support 126, is moved up or down depending on which directionguide rod 132 is rotated.

[0151] Each hole 140 includes an inside surface (not shown). It ispreferred that the inside surface of hole 140 be generally perpendicularto surface 128 of insert support 126 so that when insert support 126 israised and lowered surface 128 of insert support 126 remains parallel tosurface 124 of housing support 122. This perpendicular raising andlowering of insert support 126 is preferred because it ensures thatseals 28 and 30 of each reactor 10 engage simultaneously when eachinsert 16 is lowered into its corresponding housing 12-receptacle 22combination as insert support 126 is lowered. If surface 128 of insertsupport 126 did not remain parallel to surface 124 of housing support122 not every reactor 10 of array 120 would be sealed. Some of the seals28 and 30 would engage properly, while other seals 28, 30 would not comeinto contact with their corresponding housings 12 or receptacles 22 andwould fail to properly seal certain reactors 10. Still other seals 28and 30 could pinch or bind within their corresponding reactors 10,causing a problem when insert support 126 is attempted to be raisedbecause certain inserts 16 would stick within their correspondinghousings 12.

[0152] Each stationary ring 136 also includes a hole 142 for acorresponding guide rod 132 to pass through. Stationary ring 136 isanchored to a stationary support 144 of array 120 so that it remainsstationary while guide rod 132 rotates. Stationary ring 136 keeps guiderod 132 in position while it is rotated so that insert support 126 israised and lowered instead of guide rod 132. Each hole 142 is threaded,like its counterpart hole 140 in guide ring 134. Each hole 142 includesan inside surface (not shown) that is preferred to be generallyperpendicular to the plane of surface 124 of housing support 122 so thatsurface 124 of housing support 122 and surface 128 of insert support 126remain parallel throughout operation of quick-connect system 130.Stationary ring 136 could be anchored by any method to any stationarymember of array 120, but it is preferred that it be anchored tosomething near insert support 126 so that guide rod 132 need not beexcessively long. In one embodiment, stationary rings 136 are shown tobe anchored by anchors 146 to support 144 of housing support 122, asshown in FIG. 7.

[0153] Each guide rod 132 has a corresponding wheel 138 which is used torotate guide rod 132. Each wheel 138 is attached to an end of guide rod132 and may include a handle 148. If more than one guide rod 132 isused, as shown in FIG. 7, it is preferred that the rotation of guiderods 132 be synchronized to ensure that support 122 or 126 remains in ahorizontal plane throughout operation of quick-connect system 130. Ameans that could accomplish this would be coupling the rods with a beltsystem (not show) so that both guide rods 132 rotate the same amount atthe same time.

[0154] Although a quick-connect system 130 with guide rods 132, rings134, 136 and wheels 138 is described, the present invention is notlimited to a quick-connect system 130 with these embodiments. Othermeans could be used to ensure that support plates 122 and 126 remain ina horizontal plane and remain parallel to each other, such as aprecision rail guide system attached to support plates 122 and 126. Oneof ordinary skill in the art will appreciate the many types of systemsthat could be used to raise and lower support plates 122 and 126 andstill remain within the scope of the present invention.

[0155] Guide rods 132, guide rings 134 and stationary rings 136 can bepurchased from a supplier so that a predetermined precision can beprovided by quick-connect system 130. Examples are catalog numbers S151101900, S 151201023, S 150600010 and S 159111020 from Rexroth BoschGroup.

[0156] 5. Common Feed Reservoirs

[0157] Array 120 also creates the need for fewer feed reservoirs tostore feed liquids and gases to be introduced to the reactors 10 inarray 120. Only one liquid feed reservoir 150 is required to introduceliquid feed through injectors 48 associated with each of the reactors 10of array 120 because each reactor 10 of array 120 is performing the samereaction, with the same liquid feed. Similarly, only one gas feedreservoir 152 is required to introduce feed to the gas feed inlets 50associated with each header 14. Also, if the diluent gas is the same gasas the gas feed, a third reservoir is unnecessary so that only liquidfeed reservoir 150 and a gas feed reservoir 152 are required for theoperation of array 120. However, if a gas other than the gas feed isused as the diluent gas, a third reservoir (not shown) for the diluentgas would be required.

[0158] In some cases it may be desirable to introduce the liquid feed,gas feed and diluent gas to reactors 10 in array 120 in measured amountsso that the exact amount of each substance entering each reactor 10 isknown. It is desirable to do this because the combination of knowing howmuch reactant or diluent gas is introduced to each reactor 10 and thecomposition of the product gas exiting each reactor 10 can be used tocalculate the activity, feed conversion, major product and byproductselectivities and yields for each catalyst 24 in each reactor 10.

[0159] 6. Sampling and Analyzing

[0160] Array 120 is used to evaluate catalysts by determining theiractivity and selectivity. To accomplish this, at least a portion of eachof the product mixtures flowing through each product conduit 40 issampled and analyzed to determine its composition. Preferably, analyzer112 uses any one of the following analytic techniques to determine eachproduct gases composition; spectroscopy, spectrometry, chromatography,nuclear magnetic resonance, or a combination thereof.

[0161] 7. Reaction Heater

[0162] As with individual reactor 10, array 120 includes reaction heater108 shown in FIG. 6. Reaction heater 108 of array 120 provides heat forreaction zones 26 so that catalysts 24 can be kept at a controlledconstant temperature. Reaction heater 108 can be any type of heater toprovide the heat needed for reaction zones 26, such as analuminum-bronze oven using electrical resistance heating.

[0163] Although FIG. 6 shows a single reaction heater 108 common to allreactors 10 in array 120, in some cases it may be desirable that eachreactor 10 in array 120 have its own corresponding reaction heater 108so that different reactors 10 in array 120 may be kept at differenttemperatures. Similarly, it may be desirable in some cases to have twoor more reaction heaters 108, each reaction heater 108 providing energyfor one or more reactors 10 in array 120 so that there are blocks ofreactors 10 operating at different reaction temperatures.

[0164] D. Process of Evaporating and Reacting in an Array of Reactors

[0165] The process of vaporizing liquid feed and reacting the resultingvapor in the presence of catalyst 24 within each reactor 10 of array 120is similar to the process for an individual reactor 10. The processincludes the steps of introducing liquid feed to a plurality of reactors10, heating the liquid feed within each reactor 10, vaporizing theheated liquid feed within each reactor 10 to form a vapor andcontacting, at predetermined reaction conditions, the vapor withcatalyst 24 in each reactor 10 to form a product.

[0166] The liquid feed is introduced to each evaporation zone 18 inarray 120 simultaneously through injectors 48 so that reactors 10 ofarray 120 are operating in parallel. The liquid feed in each reactor 10is contacted with packing 76 and then heated within each reactor 10until it is vaporized within evaporation zones 18. Evaporator heater 20provides the heat for each reactor 10 in array 120 so that the liquidfeed in each bed 78 reaches its bubble point very soon after it isinjected into bed 78.

[0167] The vapor in each reactor 10 then passes into receptacle 22 ofeach reactor 10 through fluid permeable member 80. As with individualreactor 10, a gas feed may be introduced in some cases and contactedwith catalyst 24 and vapor to react and form a product gas.

[0168] After passing through fluid permeable member 80 and into reactionzone 26 of each reactor 10, the vapor and the gas feed, if present, areheated to a predetermined temperature by reaction heater 108. A singlereaction heater 108 may be used to provide the heat necessary tomaintain a predetermined temperature within each of the reaction zones26, or multiple reaction heaters 108 may be used to heat individualreaction zones 26, or blocks of reaction zones 26.

[0169] The temperature of catalyst 24 in each reaction zone 26 isconstantly measured with a thermocouple 54. This temperature is thenused to control the setting of reaction heater 108 of array 120, or ofthe individual corresponding heater for that particular reaction zone26, or block of reaction zones 26 as described above.

[0170] After being heated to a predetermined temperature, the vapor, thegas feed and catalyst 24 are contacted in each reaction zone 26 of eachreactor 10 in array 120 so that they react and form a product mixture ofa product gas, byproducts and unreacted feeds. The product mixture thenexits from each of the reactors 10 through a corresponding productconduit 40. As with a single reactor 10, each of the product mixturesmay be diluted with a diluent gas that is mixed with the productmixtures in a corresponding mixing zone 110 after the product has beenformed in each of the reaction zones 26.

[0171] It is preferred that the chemical composition of the liquid feed,the gas feed and the diluent gas be known and that the liquid feed, thegas feed and the diluent gas be introduced to each reactor 10 of array120 in measured.

[0172] At least a portion of each of the product mixtures is sampled andanalyzed by a corresponding analyzer 112 to determine its chemicalcomposition so that the activity, feed conversion, major product andbyproduct selectivities and yields for each catalyst 24 may becalculated.

[0173] Several advantages of the present invention are readily apparent.The evaporation zone is versatile because it allows liquid phase feedsto be fed as a gaseous fluid to a variety of different types oftreatment zones. Feeds of different phases may be mixed and fed as agaseous mixture to the treatment zone. For example, a liquid phase feedmay be vaporized and combined with a gas phase feed to form a continuoussupply of a gaseous mixture. With both the evaporation zone and thetreatment zone being in the same process vessel any need to transportthe gaseous feed through heat-traced conduits has been eliminatedthereby minimizing the possibility of feed components condensing out ofthe gaseous mixture prior to encountering the treatment zone. . Inparticular, the inventive evaporation zone can be located within aprocess vessel that can be easily and quickly assembled and disassembledusing seals. The vaporization of the liquid feed is accomplished withoutcompromising the seals that allow the process vessel to be easilyassembled.

[0174] The present invention should not be limited to theabove-described embodiments, but should be limited solely by thefollowing claims.

What is claimed is:
 1. A process vessel for evaporating a liquid feedand treating the resulting vapor comprising: an evaporation zone; aninjector having an orifice where said orifice is in the evaporationzone; at least one evaporation surface for evaporating feed andgenerating vapor, said evaporation surface located in the evaporationzone; the injector orifice and the evaporation surface positioned toprevent the formation of a drop at the orifice; a treatment zone; and atleast one heater associated with at least a portion of the processvessel.
 2. A process vessel according to claim 1, wherein theevaporation surface is selected from the group consisting of a porousmonolith, a plate, a cone, and combinations thereof.
 3. A process vesselaccording to claim 1, wherein the evaporation surface is a bedcontaining packing.
 4. A process vessel according to claim 3, whereinthe evaporation zone has an inside diameter, the packing has a diameter,and the diameter of the packing is less than or equal to about 10% ofthe inside diameter of the evaporation zone.
 5. A process vesselaccording to claim 3, wherein the packing has a diameter that is betweenabout 0.21 mm and about 0.42 mm
 6. A process vessel according to claim3, wherein the orifice has a diameter, the packing has a minimumdiameter and the diameter of the orifice is smaller than the minimumdiameter of the packing.
 7. A process vessel according to claim 1,wherein a gap formed between the orifice and the evaporation surface issmaller than a predicted diameter of a droplet forming at the orifice.8. A process vessel according to claim 1, wherein a gap formed betweenthe orifice and the evaporation surface is smaller than a diameter of adroplet forming at the orifice as predicted by the Young-LaPlaceequation.
 9. A process vessel according to claim 1, wherein theevaporation surface is inert.
 10. A process vessel for evaporating aliquid feed and treating the resulting vapor comprising: an evaporationzone; a treatment zone; an insert containing at least one evaporationsurface for evaporating feed and generating vapor, said insertpositioned within the process vessel so that the evaporation surface iswithin the evaporation zone; a solids receptacle containing solidparticles for treating the vapor, said solids receptacle positionedwithin the process vessel so that the solid particles are within thetreatment zone; a housing having an inlet and an outlet and having thesolids receptacle nested within the housing and the insert nested withinthe solids receptacle; and at least one heater associated with at leasta portion of the process vessel.
 11. A process vessel according to claim10, wherein the evaporation surface is selected from the groupconsisting of a bed containing packing, a porous monolith, a plate, acone, and combinations thereof.
 12. A process vessel according to claim10, wherein the insert is removable.
 13. A process vessel according toclaim 10, wherein the solids receptacle is removable.
 14. A processvessel according to claim 10, further comprising a fluid permeablemember attached to the receptacle to retain the solids but allow fluidto pass.
 15. A process vessel according to claim 10, further comprisinga fluid permeable member attached to the insert to retain theevaporation surface but allow fluid to pass.
 16. A process vesselaccording to claim 10, further comprising an injector having an orifice,wherein said orifice is in the evaporation zone and the injector orificeand the evaporation surface are positioned relative to each other so asto prevent the formation of a drop at the orifice.
 17. A process vesselaccording to claim 10, further comprising an analyzer in fluidcommunication with the outlet of the housing.
 18. A process vesselaccording to claim 10, wherein the heater is associated primarily withthe evaporation zone and further comprising a second heater associatedprimarily with the treatment zone.
 19. A process vessel according toclaim 10, wherein said housing and said solids receptacle define adiluent inlet.
 20. An array of process vessels for evaporating a liquidfeed and treating the resulting vapor in combinatorial processescomprising a plurality of process vessels and a heater associated with aportion of the process vessels, each process vessel having: anevaporation zone; a treatment zone; an insert containing at least oneevaporation surface, the insert being positioned within the processvessel so that the evaporation surface is within the evaporation zone; asolids receptacle containing solid particles for treating vapor, thesolids receptacle being positioned within the process vessel so that thesolid particles are within the treatment zone; and a housing having atleast one inlet and at least one outlet and having the solids receptaclenested within the housing and the insert nested within the solidsreceptacle.
 21. An array according to claim 20, wherein the inserts areremovable.
 22. An array according to claim 20, wherein the receptaclesare removable.
 23. An array according to claim 20, wherein theevaporation surfaces are selected from the group consisting of a bedcontaining packing, a porous monolith, a plate, a cone, and combinationsthereof.
 24. An array according to claim 20, wherein the housings andthe solids receptacles define diluent inlets.
 25. A process forvaporizing a liquid feed and treating the resulting vapor comprising:providing a process vessel having a housing encasing an evaporation zoneand a treatment zone; nesting an insert having at least one evaporationsurface within the housing so that the evaporation surface is within theevaporation zone; providing an injector having an orifice; positioningthe injector orifice and the evaporation surface to provide apredetermined gap therebetween to prevent the formation of a liquid dropat the orifice; injecting the liquid feed into the insert through theinjector orifice; heating the liquid feed so that it will be at least atits bubble point while it is in contact with the evaporation surface togenerate a vapor; flowing the vapor to the treatment zone; and treatingthe vapor within the treatment zone to generate an effluent.
 26. Aprocess according to claim 25, further comprising analyzing theeffluent.
 27. A process according to claim 25, further comprisingdiluting the effluent.
 28. A process for evaporating a liquid feed andtreating the resulting vapor comprising: providing a process vesselhaving a housing encasing an evaporation zone and a treatment zone;providing packing in the evaporation zone; providing an injector havingan orifice; positioning the orifice and the packing so that there is apredetermined gap therebetween to interfere with the formation of aliquid drop at the orifice; injecting the liquid feed into theevaporation zone through the injector orifice; heating the liquid feedso that it will be at least at its bubble point within the evaporationzone to generate a vapor; flowing the vapor to the treatment zone; andtreating the vapor within the treatment zone to generate an effluent.29. A process according to claim 28, further comprising analyzing theeffluent.
 30. A process according to claim 28, further comprisingdiluting the effluent.
 31. A process according to claim 28, furthercomprising forming a thin liquid film of the liquid feed on the packing.32. A process according to claim 28, further comprising mixing the vaporwith a gas feed within the evaporation zone.
 33. A process according toclaim 28, further comprising positioning the orifice and the packing sothat the gap is smaller than a predicted diameter of a liquid dropletforming at the injector orifice.
 34. A process according to claim 28,further comprising positioning the orifice and the packing so that thegap is smaller than a diameter of a liquid droplet forming at theinjector orifice predicted by the Young-LaPlace equation.
 35. Acombinatorial process for evaporating a set of liquid feeds and treatingthe resulting vapors comprising: providing an array of process vessels,each vessel havinging both an evaporation zone and a treatment zone;providing packing in the evaporation zones, the packing forming beds;providing injectors having orifices; positioning the orifices and thepacking so that there is a predetermined gap therebetween within eachprocess vessel to interfere with the formation of a liquid drop at theorifices; injecting the liquid feeds into the evaporation zones throughinjector orifices; heating the liquid feeds so that they will be atleast at their bubble points within the beds of packing to generatevapors; flowing the vapors to the treatment zones; treating the vaporswithin the treatment zones to generate effluents.
 36. A process forevaporating a liquid feed and treating the resultant vapors comprising:providing process a vessel having an evaporation zone and a treatmentzone; placing an insert having at least one evaporation surface forevaporating feed positioned within the process vessel so that theevaporation surface is within the evaporation zone; injecting the liquidfeed into the evaporation zone; heating the liquid feed so that it willbe at least at its bubble point while in contact with the evaporationsurface generate a vapor; flowing the vapor to the treatment zone; andtreating the vapor in the treatment zone to generate an effluent.
 37. Aprocess according to claim 36, further comprising providing anevaporation surface that is selected from the group consisting of a bedcontaining packing, a porous monolith, a plate, a cone, and combinationsthereof.
 38. A process according to claim 36, further comprisingdiluting the effluent.
 39. A process according to claim 36, furthercomprising analyzing the effluent.